Package or Bundle?

Applications on Mac OS have always looked like a single executable file. This is a far cry from Windows application storage, where applications include a single executable file and a slew of shared library files and a number of specific changes to the operating system’s Registry and… well, you get the idea. But in Mac OS, the situation is not much better. The one-file-per-application methodology is just a well-meaning sham.

Earlier versions of Mac OS kept applications in one file, called a package. To install an application, all you had to do (essentially) was drag the icon for the application (package) from a CD or floppy disk to your hard drive. To remove that application, you would simply drag the package to the Trash.